Socket for post stressed concrete wires



June 20, 1961 T. J. GUTT SOCKET FOR POST STRESSED CONCRETE WIRES Filed Dec. 18, 1957 FIG.

INVENTOR. TADIUS J. GUTT A ATTORNEYS.

United States Patent 2,988,794 SOCKET FOR POST STRESSED CONCRETE WIRES Tadius J. Gutt, Maple Heights, Ohio, assignor to George Rackle & Sons Company, Garfield Heights, Ohio, a corporation of Ohio Filed Dec. '18, 1957, Ser. No. 703,540 Claims. (Cl. 24-123) This invention, relating as indicated to a socket for post stressed concrete wires, is particularly directed to a socket which is adapted to hold buttons of a multiplicity of wires for a concrete beam or other structure. The buttons are formed by the machine of the type described in Patent No. 2,728,978.

In general in connection with post stressed concrete beams, it has been found that there are some advantages to post stressing, as distinguished from pretensioning, concrete structures. There has been difficulty in the past in assembling a socket structure and/ or other means for tensioning the wires in the beam, and in general various structures are available, including sockets, using a buttonhead technique or an upset wire head, and sometimes even a double buttonhead technique whereby a hydraulic tensioning unit engages a socket or other pulling arrangement and tensions the second button or double button of the wires. Engaging units are employed in connection with other devices involving a threaded arrangement on the hydraulic tensioning unit for pulling the socket. However, all of these devices involve sockets which must be threaded on in some instances before heading of the wires, and some of which have no screw tthread means of engagement.

This arrangement is particularly directed to a socket which may be threaded after the wires are assembled, as distinguished from a Wedge clamping device, and involves a button head in which the buttonhead takes the complete stress of the wire and must be stronger than the tensile strength of the wire itself. That is .to say, the wire must break before the button will distort or pull off.

This invention is particularly directed to a spider socket arrangement of annular construction having passages from the exterior side and having a lower flange element or annular section extending outwardly from the internal flange arrangement. Mating with this structure, but other than in a wedge action, is a wire retaining ring adapted to fit over the socket and having mating grooves with the axially extending grooves of the socket in order to permit the wires to extend through the socket and through the wire retaining ring and to be held partially on the wire retaining ring and partially on the socket. The socket furthermore has a threaded section internally of the socket which is adapted to be engaged by a hydraulic tensioning unit.

The advantages of this system are that once the wires are headed by the machine of the type disclosed in Patent No. 2,728,978 they may be fitted in and around the spider arrangement, and the wires and buttons extending outwardly therefrom bent inwardly a slight amount so that the wire retaining ring may be fitted over the head and onto the mating portion of the socket. 'In this arrangement the socket may be pulled up and the buttonheads fitted partially on the retaining ring and partially on the socket. After tensioning, shims or other arrangements may be employed and the hydraulic tensioning unit removed. Grouting material may be placed through the center of the socket to permanently hold the wires in position.

An object of this invention is to provide a new and improved wire socket for post stressed concrete.

A further object of this invention is to provide a new and improved spider socket having a mating wire retaining ring with matching grooves for the wires.

Another object of this invention is to provide a new and improved wire socket and method of stressing post stressed concrete structures in which a socket member has an externally extending flange with axially extending grooves therein to the periphery of the socket and a mating retaining ring having corresponding grooves for axially extending wires, whereby the socket may be stressed and the retaining ring and socket would hold the wires and the buttonheads in position.

Another object of this invention is to provide a new and improved method of stressing post stressed concrete structures without the necessity of threading on a socket arrangement before buttonheads are formed upon the wires.

To the accomplishment of the foregoing and related ends, said invention then consists of the means hereinafter fully described and particularly pointed out in the claims; the following description setting forth in detail one approved means of carrying out the invention, such dis closed means, however, constituting but one of the various ways in which the principles of the invention may be used.

In the drawings:

FIG. 1 is a sectional assembly view of the socket shown in position with the hydraulic tensioning unit for gripping the buttonhead wires;

FIG. 2 is an exploded view of the socket and wire retaining ring;

FIG. 3 is a cross-sectional view along the line 33 of FIG. 1; and

FIG. 4 is a cross-sectional view along the line 4-4 of FIG. 1.

In FIG. 1 of the drawings 10 shows a concrete structure which may be a beam or other means, and 11 shows a wire, of which there may be a multiplicity. Each of these wires is formed with a buttonhead as at 13. On top of the concrete structure there may be a bearing plate or other means, though in all instances this may not be required, as shown at 14L A socket arrangement for tensioning the buttonhead wires is shown at 15. The socket is internally threaded as at 16 and is adapted to be contacted by a threaded section as shown at 18 of an hydraulic tensioning unit 19. The hydraulic tensioning unit has a support or post arrangement 20 which may contact a bearing plate 14. The external side or periphery of the socket is spider shaped having a multiplicity of apertures, for example, at 22, extending to a curved inner portion 21. Each of the apertures would be equally spaced from the center of the socket. The exact number of peripheral sections, for example, at 2.2, is indefinite and a lesser number may be used. That is to say, in the drawings only half of the extended peripheral portions 22 may be required to support the structure. The tapered section 23 of these members need not be tapered except for manufacturing purposes. The grooves shown at 21 extend to the upper portion of the socket as at 24, and they are actually axial grooves parallel to the axis of the socket.

A wire retaining ring 25 shown in connection with FIG. 2 has a multiplicity of mating curved portions 26 which are adapted to surround the wire section and support the buttonhead 13 of the wires.- The wire retain: ing ring would be cylindrical on its exterior face and would surround the wires. The number of wires shown is twelve in the view indicated, but a lesser number or greater number may be required depending upon the structure involved in the post stressed concrete beam or the like.

On the interior side of the unit as at 16 would be a threaded portion into which the hydraulic tensioning unit or jack may be threaded. A shim arrangement 28 is shown which could be split into spherical portions, though three or more portions may be employed under special conditions. In general the shims would be of varying dimensions depending upon the tension desired, and once the socket unit is tensioned the shims would be positioned between the socket and the bearing plate in order that the desired tension in-the wires would be present when the tension from the hydraulic tensioning unit is removed.

The entire stress upon the wires is taken up in the button which rests on the wire retaining ring and on the internal side of the socket arrangement. There is no wedging action between the socket and the retaining ring to grip the wires.

In general in connection with these sockets, they are positioned within the beam in a housing with limited space on the exterior side. Consequently, it is not desirous to have additional structures on the exterior side of the wire retaining wire or the socket as this may necessitate enlarging of the opening within the beam or concrete structure.

After the shims are positioned, it will be seen that the hydraulic tensioning unit would be removed and one or more shims would be positioned beneath the socket. Grouting material may be placed within the unit through the opening shown at into which the threaded section of the tensioning unit had been positioned. Upon hardening the grout, of course, the wires would be securely fixed into position.

The invention involved herein is particularly useful in connection with the stressing of post stressed concrete beams and simplifies the procedure greatly, in that after the beam is cast, or other structure, wires may be threaded through an aperture or other opening in the beam. Generally it is diificult to head the units after a socket, spider or other arrangement is positioned over the wires. It would be preferable to head the units and then insert the socket. adapted for that purpose as the wires may be spread apart and a socket placed in the middle. The wires would then be threaded through a short distance, and the wire retaining ring would be positioned over the ends of the wire, and this may be bent slightly inwardly. After it is positioned upon the socket, the wires may be tightened up. The tensioning unit may then be applied, and the shims positioned. The particular advantage of this technique is that the spider or socket arrangement need not be inserted in the wires before heading. Frequently, in this event, a cumbersome operation is involved if a heading for some reason or other spoils one of the wires. A new wire must be inserted, and this is a troublesome, time consuming operation.

The method then involved heading a multiplicity of wires, inserting a spider-socket arrangement between the wires so that the wires are within each of the radial apertures of the spider, stretching the wires so that the heads are outwardly from the spider-socket, passing over the heads a wire retaining ring adapted to mate with the socket and then pulling the socket to stretch the wire and inserting shims or other retaining means around the socket. The grouting operation follows after removal of the tension or pressurefrom the jack. The materials of which the socket or wire retaining ring may be made are, for example, a forging of a steel, such as SAE 1040, and equivalent alloy or other materials may be employed under special conditions.

This invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all'changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

I claim:

1.. An anchoring and stressing socket for post stressed This arrangement is particularly 1 concrete wires, said socket comprising a one member cylindrical conformation having a central aperture therethrough and an enlarged base portion, a multiplicity of radial apertures in said base portion forming a spider arrangement, each of said apertures terminating in a groove which is substantially parallel to the central aperture, a second member forming an upper portion of lesser diameter than said enlarged base portion of said one member extending outwardly from said groove, a retaining ring adapted to mate with and fitting over said upper portion of the socket having a corresponding number of grooves on the internal face of said retaining ring adapted to permit wires to pass between the ring and the socket, the upper portion of the retaining ring and the socket being substantially in the same plane to provide a bearing face for the buttons of the post stressed concrete wires and thread engaging means on said one member adapted to engage the tensioning unit to stress the socket and tension the wires.

2. An anchoring and stressing socket for post stressed concrete wires having enlarged button portions adapted to engage the socket, said socket having a first member with a central aperture therethrough, a multiplicity of radial apertures in the side of the first member having longitudinally extending grooves therein, a base portion of said first member extending outwardly therefrom, a retaining ring fitting over said base portion and over the first member, the internal face of said retaining ring having a multiplicity of grooves complementing and forming wire receiving grooves with the first member, an upper face portion of the first member being substantially coplanar with an upper face portion of the retaining ring at least over an area adjacent the grooves to provide a bearing face for the button portions of the wires, and thread engaging means on said first member adapted to engage the tensioning unit to stress the socket and tension the wires.

3. An anchoring and stressing socket for post stressed concrete wires, said wires having enlarged button portions on the wires to engage the socket, said socket having a first member of generally cylindrical conformation and having a central aperture therethrough and a radially enlarged base portion, a multiplicity of radial apertures in said base portion from the exterior side forming a spider arrangement, each of said apertures terminating in a groove which is substantially parallel to the central aperture, the upper portion of said first member being of lesser diameter than the lower portion, and said lower portion extending outwardly from said longitudinally extending grooves, a retaining ring having an interior and an exterior face mating with and fitting over said lower portion of the socket having a corresponding number of grooves on the internal face of the retaining ring adapted to mate with the grooves in said first member permitting wires to pass between the retaining ring and the first member, the upper face of the retaining ring and the first member being substantially in the same plane to provide a bearing face for the enlarged button portions of the post stressed concrete wires and thread engaging means on said first member adapted to engage the tensioning unit to stress the socket and tension the wires.

4. An anchoring and stressing socket for post stressed concrete wires, said socket having a first member of generally cylindrical conformation having a central aperture therethrough, said socket having a radially enlarged base portion providing a step, a multiplicity of radial apertures in said base portion forming a spider arrangement, each of said apertures terminating in a groove which is substantially parallel to the central aperture, a retaining ring mating with and fitting over the step of the first member, said retaining ring having an internal face with a multiplicity of complementary grooves substantially parallel to the centralaperture of the first member and mating with the corresponding grooves in the first member, the upper face of said retaining ring and said first member being substantially in the same plane to provide a bearing face for the post stressed concrete wires and thread engaging means on said first member adapted to engage the tensioning unit to stress the socket and tension the wires.

5. An anchoring and stressing socket for post stressed concrete wires, said wires having enlarged button portions adapted to engage the socket, said socket having a first member of generally cylindrical conformation with a central aperture therethrough and an enlarged base portion, a multiplicity of radial apertures in said base portion forming radial tongues, spider shaped, each of said apertures terminating in a groove which is substantially parallel to the central aperture, said first member further having an upper portion of lesser radial thickness than the enlarged base portion, a retaining ring mating with and fitting on said enlarged base portion, said retaining ring having a multiplicity of longitudinally extending grooves therein mating with the grooves in the socket in the first member, the upper face of said retaining ring and said first member at least adjacent to the grooves being substantially in the same plane to provide a-bearing face for the enlarged portionse of the post stressed concrete wires and thread engaging means on said first member adapted to engage the tensioning unit to stress the socket and tension the wires.

References Cited in the file of this patent UNITED STATES PATENTS 1,656,676 Mills Jan. 17, 1928 1,953,594 Douglas Apr. 3, 1934 2,341,922 King et a1 Feb. 15, 1944 2,686,951 Seaman Aug. 24, 1954 2,867,884 Brandt Jan. 13, 1959 FOREIGN PATENTS 457,743 Canada a of 1949 694,596 Great Britain of 1953 181,068 Austria of 1955 

